Path: ns-mx!uunet!lll-winken!aunro!alberta!edson!news
From: jpenne@ee.ualberta.ca (Jerry Penner)
Newsgroups: comp.sys.apple2
Subject: Re: Accessing the HLINE command from assembly..
Message-ID: <1991Aug7.224655.7988@ee.ualberta.ca>
Date: 7 Aug 91 22:46:55 GMT
References: <33204.apple.net@pro-party>
Sender: news@ee.ualberta.ca
Organization: University of Alberta Electrical Engineering
Lines: 29

In article <33204.apple.net@pro-party> ndurham@pro-party.cts.com (Niall Durham) writes:
>Can any programmer/developer tell me if it is possible to access and
>utilitze the HLINE command in basic.system from assembly?  If so, could I
>maybe get some more information?  Like if you do access it, is there any
>way to set up the cooridinates?  What about the HCOLOR command also?
>
>I don't mean to break up everyone's discussion over GS/OS and stuff, I just
>need to know a backward technological answer.

Cool.  I get to haul out the Applesoft disasm twice in one week. :-)

Yup, you can call the Applesoft (not basic.system) hi-res routines.

You have to make sure the ROM is switched in (tickle the $C082
softswitch).

HCOLOR	store color # in X-reg (0-7) and JSR $F6EC

HPLOT	Acc = YCoordinate   Xreg = Xcoord (lo byte)  Yreg = Xcoord (high byte)
	JSR	$F457

HLINE	Acc= xcoord low byte  Xreg= xcoord high  Yreg = ycoord
	JSR	$F53A

You will notice that the parameters in registers for X & Y coords are
not the same for plotting a dot or drawing a line.
-- 
Jerry Penner		  | jpenne@bode.ee.ualberta.ca
Edmonton, Alberta, Canada |  OR  alberta!bode!jpenne